1. Field of the Invention
This invention relates generally to ground proximity warning systems, and more particularly to a ground proximity warning system that provides timely alerts and warnings of an excessive descent rate through the glideslope.
2. Description of the Prior Art
Ground proximity warning systems are known. Such ground proximity warning systems advise and warn the pilot of an aircraft of a hazardous flight condition. Among the various hazardous flight conditions are an excessive descent rate, particularly during landing, and examples of warning systems designed to provide warnings of an excessive descent rate during landing are disclosed in U.S. Pat. Nos. 3,936,796, 3,947,808 and 4,060,793. Another hazardous flight condition is the deviation of the aircraft below the glideslope beam. Various warning systems have been developed to warn the pilot of such an excessive deviation below the glideslope beam, and examples of such systems ar disclosed in U.S. Pat. Nos. 3,925,791, 3,946,358 and 3,947,809. While the above systems do provide warnings of the hazardous flight conditions, they are designed to detect, such as excessive descent rate and excessive deviation below the glideslope, they operate independently and monitor only one hazardous flight condition. However, in some instances, a combination of hazardous flight conditions that individually would not pose a hazard to the aircraft can pose a hazard when their effects are combined. Consequently, systems monitoring single flight conditions may not give an optimum warning of a hazardous flight condition resulting from a combination of flight parameters. Conversely, an apparently hazardous flight condition may be tolerated if another flight condition compensates for or negates the hazard. Systems monitoring a single flight condition would be unaware of the compensating condition and could generate nuisance warnings.